ACTA BIOLOGICA CRACOVIENSIA

BIOSYNTHESIS, GENETICS, AND METABOLISM OF CAROTENOIDS
carotenoid diet to control roe pigmentation will help establish a
Kina roe export industry for New Zealand.
The current belief is that carotenoid compounds are responsible
for sea urchin roe pigmentation. Sea urchins cannot synthesise
carotenoids de novo, and are therefore dependent upon
dietary carotenoid intake, which may be assimilated selectively or
transformed to other forms.
Comparison of the carotenoid profiles extracted from Kina
tissues revealed that echinenone was the predominant carotenoid
in both light and dark pigmented roe. There were also increased
amounts fucoxanthin, astaxanthin and β-carotene being detected
in dark brown roe compared to light coloured roe. The predominant
carotenoids present in the gut wall were fucoxanthin, violaxanthin
and echinenone.
The source of echinenone in Kina roe is uncertain, as it is not
present in the natural diet of Kina, Macrocystis pyrifera (kelp),
which instead contains mainly fucoxanthin with minor amounts
of β-carotene and violaxanthin. We suggest here that echinenone
is generated from available β-carotene found at low levels in kelp.
We also suggest that the gut is therefore directly involved in the
metabolism of carotenoid compounds and that separate
carotenoid modification events are occurring in different tissues.
A four-month Kina diet trial was carried out with specially
formulated diets to evaluate the effect of increasing or decreasing
beta-carotene dietary levels on Kina roe colour. We found that by
modifying the carotenoid content in the diet, it was possible to
manipulate roe colouration and potentially assist in the development
of a Kina export market for New Zealand.
6.7.
Rapid positive selection of carotenoidsoverproducing
mutants of the yeast Phaffia
rhodozyma (Xanthophyllomyces dendrorhous)
using mixture of heavy metals as a selective
agent
Svitlana Gural 1 , Mykhailo V. Gonchar 2,3
1Institute of Animal Biology, NAAS of Ukraine, V. Stusa Str. 38,
79034 Lviv, Ukraine, g_svitlana@ukr.net
2Institute of Cell Biology, NAS of Ukraine, Drahomanova Str. 4/16,
79005 Lviv, Ukraine, gonchar@cellbiol.lviv.ua
3Rzeszow University, Branch Campus of the Faculty of
Biotechnology, Kolbuszowa, Poland
The yeast Phaffia rhodozyma is the producer of carotenoids, such
as carotenes and xanthophylls. Biomass of this yeast can be strategic
source of compounds with a high biological activity. The wild
strains produce carotenoids in the level of about 0.3 mg/g, among
them 80% is related with antioxidant astaxanthin (Goswami G. et
al., 2010). The mutant strains were isolated with genetic blocks in
synthesis of some astaxanthin precursors (Gural et al., 2011). We
propose to select the mutants with higher levels of carotenogenesis
using a simple and rapid procedure based on positive selection on
a medium containing heavy metals. For mutagenesis, ultraviolet
irradiations, as well as nitrosoguanidine were used. As the selective
factors, compositions of mixtures of heavy metals salts (Cu 2+ , Zn 2+ ,
Co 2+ , Pb 2+ ) and (Cu 2+ , Zn 2+ , Co 2+ , Pb 2+ and Cd 2+ ) were used in different
concentrations (Iutynska et al., 2000, Bhosale P., 2004). The
survival rate as a function of the dose and metals concentration has
been estimated. Carotenoids' content in the most productive
mutants has been analyzed.
REFERENCES
GOSWAMI G, CHAUDHURI S, DUTTA D. 2010. The present perspective of
astaxanthin with reference to biosynthesis and pharmacological
importance. World J Microbiol Biotechnol. 26: 1925-1939.
Vol. 53, suppl. 1, 2011
GURAL SV, KOLYSNYK GV, KLYMYSHYN DO, GONCHAR MV. 2011.
Investigation of carotenoids' composition in the yeast mutants
Phaffia rhodozyma (Xanthophyllomyces dendrorhous).
Biotechnology. 4: 93-100 (in Ukrainian).
IUTYNSKA GO, PETRUSHA ZV, VASILYEVA TV. 2000. Toxicity and mutagenity
of heavy metals as soil pollutants. Modern problems in toxicology
2: 53-56 (in Ukrainian).
BHOSALE P. 2004. Environmental and cultural stimulants in the production
of carotenoids from microorganisms. Appl. Microbiol.
Biotechnol. 63: 351-361.
6.8.
17–22 July 2011, Krakow, Poland
Carotenoid composition in native and
commercial potato (Solanum sp.) cultivars
Rebeca Fernández-Orozco, Lourdes Gallardo-Guerrero,
Dámaso Hornero-Méndez
Departament of Food Biotechnology, Instituto de la Grasa – CSIC.
Av. Padre García Tejero, 4, 41012 Seville, Spain, hornero@cica.es
The genus Solanum comprises more than 2000 species, being
the potatoes (S. tuberosum L.) the most important, with more
than 4000 potato varieties world while, most of them developed
through man selection. Potato is, after cereals, the most important
staple food for the human population, being considered an
important source of carbohydrates and other nutrients such as
vitamin C. In the last ten years, an increasing interest has been
raised on the study of potatoes as a good source for phytonutrients
such as carotenoids and anthocyanins. For this reason, several
breeding programmes are being conducted with the aim of
increasing the carotenoid and/or anthocyanin contents in potatoes,
and as a result a particular attention has been paid to the
characterization of the old and native cultivars as a source of
genetic variability for increasing these traits, as well as to help in
the understanding of the genetic and molecular basis governing
their biosynthesis. In the present study we have characterised the
carotenoid composition of 60 potato cultivars (commercial, bred,
old and native cultivars) belonging most of them to the species S.
tuberosum subsp. tuberosum and S. tuberosum subsp. andigena,
and a few to the species S. goniocalix and S. stenotonum. The
analysis of the carotenoid profiles allowed the cultivars to be segregated
into three groups according to the presence of violaxanthin,
lutein and neoxanthin as main pigment, suggesting a different
control of the biosynthetic pathway in the three groups. In
addition, a direct correlation was found between the total
carotenoid content and the concentration of the main pigment
(namely violaxanthin, lutein and neoxanthin), corresponding the
varieties with higher carotenoid content to those having violaxanthin
as main pigment. The presence of xanthophyll esters has
also been investigated, with a direct correlation being observed
for the carotenoid content and the fraction of carotenoids being
esterified, which is in accordance with the idea that the esterification
process allows the plants to accumulate these lipophyllic
compounds within the plastids. Therefore, the presence of xanthophyll
esters should be phenotypic character to be included in
the breeding studies, and more efforts should be dedicated to the
understanding of the biochemical process leading to this structural
modification of carotenoids in plants.
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